Irish nationalists opposed to Northern Ireland’s peace process have told the BBC they were behind a fatal shooting last Friday at a Dublin hotel, saying it was retaliation for the killing of an ally in 2012.

Police remove a body from the scene of a shooting at the Regency Hotel in Dublin on Feb. 5.Reuters

Another man was shot and killed in north Dublin on Monday evening, Justice Minister Frances Fitzgerald said in a statement. Local media reported that it was a reprisal for Friday’s murder.

A spokesman for Ireland’s police said it was investigating the shooting and could not confirm if the two were linked.

Fitzgerald described the manner of the attack on Friday, which happened in broad daylight with children present, just 2.5 miles from central Dublin, as “unprecedented.”

In a statement to the BBC in which an agreed codeword was used, a man claiming to speak on behalf of the leadership of the dissident group Continuity IRA said its members were responsible, saying it was retaliation for the fatal shooting in September 2012 of Alan Ryan, another militant nationalist.

“We are not going to stand back and allow drug dealers and criminals to target republicans,” the BBC quoted the man as saying. “This will not be an isolated incident.”

Asked about the claim of responsibility, Fitzgerald on Monday said it would be thoroughly investigated.

Irish Republicans oppose British rule in Northern Ireland and many defend the use of force against it. Dissident Republicans do not recognize a 1998 ceasefire in Northern Ireland by the Provisional Irish Republican Army, which had fought British rule for three decades.